As the state of the art of integrated circuits (ICs) has advanced, designers have reduced the power supply voltage required to power the circuits. However, in order to provide a fixed amount of power to an IC device, as the supply voltage (V) is decreased, the current (I) consumed by the device must necessarily increase. The higher current flowing in the IC device generally results in an increased amount of power loss and/or noise in the device.
It is known that by increasing the voltage supplied to an IC device, a fixed amount of power may be delivered at substantially less current, thereby reducing power lost, for example, to IR heating and/or inductive noise (Ldi/dt) which is proportional to the current in the device. To reduce noise, an IC device may be separated into dedicated regions based, at least in part, on circuit functionality. For example, an IC may include an analog section comprising primarily analog circuitry (e.g., input/output buffers, bias generators, etc.) and a digital section comprising primarily digital circuitry (e.g., digital control circuits, digital signal processor, logic gates, etc.). These regions are generally isolated, to at least some extent, from one another so as to reduce the likelihood that noise generated by one region will be undesirably introduced into another region. However, essentially all current flowing in the IC device is eventually returned (e.g., via a substrate in the IC device) to a common ground, and therefore such a circuit arrangement typically does not noticeably reduce leakage current effects in the device.
It is also known to use separate conductive planes (e.g., metal layers) in an IC device for conveying multiple supply voltages in the device, with each supply voltage being assigned its own metal layer in the device. Capacitors and/or inductors are commonly used to stabilize the respective voltages on the planes and to decouple noise. However, these capacitors are often located too far from the circuit(s) sharing that supply plane. This results in the loss of power due, at least in part, to the distributed IR drop of the local leakages of many devices in a deep-submicron logic chip.
Accordingly, there exists a need for an improved IC architecture having reduced power loss and/or noise that does not suffer from one or more of the problems exhibited by conventional IC arrangements.